The regulation of the temperature of electronic devices like processors due to heat generated inside is an important consideration during the design of an electronic device. Cooling is important because if left unchecked, heat can cause electronic devices to malfunction during use or lead to premature device failure. As improvements in processor speed occur, the amount of heat generated by the faster processors also increases.
Another factor that aggravates the need for improved heat removal cooling systems is the trend towards making computing devices smaller and especially thinner. The trend toward smaller and thinner electronic devices having larger, faster processors renders the traditional heat removal cooling systems inadequate for several reasons. First, smaller devices having faster processors result in an increased density of heat producing by electronic devices leading to higher concentrations of heat. Second, a decreased amount of space is available for temperature regulating devices. In order to decrease the system space, some designs offering a single heat dissipation module that able to cool several electronic components.
There are numerous designs of cooling systems for electronic devices that include a blower-assisted heatsink located directly at the electronic device. But the problems became more dramatically when an electronic structure, for example, like an embedded system comprises several electronic devices. In this case it is practically impossible to provide a coincidence of the contact surfaces of the electronic devices with the contact surface of the heatsink. Therefore, it is very difficult to provide a good tight contact with low thermal resistance between each heatsink and electronic devices compared to the heatsinks that are individually installed on every electronic component. As a result, when a single common heatsink or heat spreader coupled with several electronic devices, it's nearly impossible to provide tight attachment with every processor and the thermal resistance increases drastically. Therefore the cooling efficiency of such system is not sufficient enough.
For solving the mentioned problem related with cooling of several electronic devices the heat transfer structures used often between the electronic devices and the heatsink. Special designed heat transfer elements with certain flexibility like heat pipes or high heat conducting elements that allow providing a good thermal contact with the electronic devices and heatsink.
There are known devices of this type with special designed flexible heat pipes, for example, US Patent Application No. 2004/0240184 “Circuit Cooling Apparatus”. The heat transfer structure according to this design comprises two heat pipes providing linear and angular displacements due to their special corrugated shaped design. The each heat pipe comprises a condenser, an evaporator and two separated wick members spaced inside of the corrugated container. But such design is complicated and, therefore expensive and not reliable enough.
There is also a heat transmission apparatus according to the Japanese Patent No. JP2005142328 designed for solving the same problem when several electronic devices are placed at the same circuit board. The heat transmission apparatus comprises heat transmitting means which are formed of different material having both thermal conductivity and resiliency and are arranged in a space between the electronic devices and the heat dissipated element like a heatsink. However, in comparison with heat pipes these heat transmitting means having much lower heat conductivity that decreases the system cooling efficiency.
There is also known the heat transfer structure described in the Japanese Patent No. JP9232781 “IC Cooling Structure”. According to this patent the design comprises the spiral bodies which are respectively constituted of a plurality of fine wires having high heat conductivity and consist of a flexible metal. Like a previous design, in comparison with heat pipes these spiral bodies have much lower heat conductivity and much higher thermal resistance. Therefore it has not sufficient cooling efficiency.
The main problem of all known heat transfer structures that cools several electronic devices located at one circuit board—is that all designs can not resolve the contradiction between the high cooling efficiency on the one hand and complicity and reliability on the other hand.
Therefore, it would be generally desirable to provide a low profile reliable and not complicated and efficient heat transfer structure for several electronic devices that overcomes mentioned problem.